Sean Milligan

Software Engineer at MongoDB

Greater Seattle Area

About

Experience

  • Software Engineer at MongoDB
    Apr 2026 - Present · 3 mos

    Node.js Driver

  • Software Engineer at Google
    Aug 2021 - Apr 2026 · 4 yrs 9 mos

    Virtual I/O (org) Storage Optimized Machines (team) - Building out support for the virtualization of NVMe storage devices for Google Cloud. - Ensuring first-class experience for Windows VMs booting from or writing to NVMe devices.

  • Software Engineer at Microsoft
    Jan 2018 - Aug 2021 · 3 yrs 8 mos

    Microsoft Cloud Infrastructure Operations (Org) Data Center Resource Management (Team) Developing reservation system software to manage server placements in Microsoft datacenters. Software accounts for changing constraints including space, power, cooling, and networking capacities over time as servers deploy and decommission. - Implemented server auto-placement in data centers using immutable data structures, functional programming paradigms, and time-series data. Best fit was optimized over multiple constraints compared using z-scores. - Implemented “what-if” analysis with rewind and replay capabilities to optimize constraints and projections. - Implemented cross-team event-driven data synchronization services using Azure Service Bus. - Designed RESTful APIs including API and database models, database schema, use cases, and goals. - Configured security settings such as auto-rotating X509 certificates, JWT-based authentication, TLS, and encryption at rest. Migrated services from thumbprint to CNAME-based X509 certificate retrieval for JEDI. - Set-up monitoring and auto-created tickets for service metrics such as status codes and message queue depth. - Maintained feature and data parity during major system rewrites using proxies, adaptors, and shadow testing. - Enhanced dev productivity with tools to inspect queues, caches, blob storage, and decode illegible file formats. - Implemented arial view of datacenter grid using React and Redux. - Triaged live-site issues, balancing short term mitigation with long term problem resolution.

  • Teaching Assistant at Stony Brook University
    Aug 2016 - Dec 2017 · 1 yr 5 mos

    Instructed a weekly class of 15-20 students on topics such as binary number formats, boolean logic, processor design, and MIPS32 Assembly programming. Wrote the design specification of MIPS32 Assembly project assignments. Manually inspected student code when concerns over grading script issues are raised. Answered student questions while proctoring quizzes and exams, and in online forums.

  • Financial Services Representative at Teachers Federal Credit Union
    Sep 2013 - Jan 2016 · 2 yrs 5 mos

    Process loan applications and disburse approved loans. Cross-sell different accounts and ancillary services. Notarize documents for credit union members.